1. Field of the Invention
The present invention relates to a hydrodynamic coupling device, in particular a hydrodynamic torque converter, including a casing arrangement and a turbine rotor which can be rotated about an axis of rotation in the casing arrangement. The turbine rotor has a turbine rotor shell which supports a plurality of turbine rotor blades, and a turbine rotor hub which is coupled or can be coupled to a drive element for joint rotation. A lock-up clutch arrangement is provided for the optional production of a torque transmission connection between the turbine rotor and the casing arrangement, and torsional vibration damper arrangement couples the turbine rotor for torque transmission to a coupling element of the lock-up clutch arrangement. A positive drive arrangement is provided on the torsional vibration damper arrangement, which positive drive arrangement is in drive engagement for torque transmission with a mating positive drive arrangement on the turbine rotor.
2. Description of the Related Art
A hydrodynamic coupling device of this type is known, for example, from U.S. Pat. No. 5,813,227. In this known hydrodynamic coupling device, a central disk element of the torsional vibration damping arrangement, which ultimately acts as a coupling element, has teeth protruding radially inward as a positive drive arrangement, which teeth are in interdigitating engagement with mating teeth on a drive element. This drive element is welded onto an outer side of the turbine rotor shell. On the other side, the turbine rotor blades are connected to the turbine rotor shell or are in contact with the latter. This construction has the problem that the attachment of the drive element by welding can lead to deformations in the region of the turbine rotor shell so that the flow characteristics of the same can be adversely affected.
DE 198 38 445 A1 reveals a hydrodynamic coupling device in the form of a hydrodynamic torque converter in which a region of the torsional vibration damping arrangement to be coupled to the turbine rotor is permanently coupled to the turbine rotor shell by riveting. In general, the riveting also represents an operational procedure which can only be undertaken after the connection of the turbine rotor shell to the turbine rotor blades so that, here again, it is not possible to ensure that no deformations of the turbine rotor occur per se during this operational procedure.
It is an object of the present invention to make available a hydrodynamic coupling device in which the torque transmission connection between a torsional vibration damper arrangement and a turbine rotor can be produced in a simple manner without the danger of any type of impairment being generated in the region of the turbine rotor.
According to the present invention, this object is achieved by a hydrodynamic coupling device, in particular a hydrodynamic torque converter, including a casing arrangement and a turbine rotor which can be rotated about an axis of rotation in the casing arrangement. The turbine rotor has a turbine rotor shell which supports a plurality of turbine rotor blades, and a turbine rotor hub which is coupled or can be coupled to a drive element for joint rotation. A lock-up clutch arrangement is provided for the optional transmission of torque between the turbine rotor and the casing arrangement, a torsional vibration damper arrangement and couples the turbine rotor for torque transmission to a coupling element of the lock-up clutch arrangement. A positive drive arrangement is provided on the torsional vibration damper arrangement, which positive drive arrangement is in drive engagement for torque transmission with a mating positive drive arrangement on the turbine rotor.
According to the invention, the positive drive arrangement is formed integrally on the turbine rotor shell.
The provision of this mating positive drive arrangement as an integral constituent of the turbine rotor shell makes it possible to form this arrangement as early as during the manufacture of the turbine rotor shell, i.e. at a time when the turbine rotor shell has not already been necessarily combined with the turbine rotor blades. It is then unnecessary to engage in further measures when the turbine rotor shell is joined together with the turbine rotor blades in order to be able to make such a mating positive drive arrangement available. Finally, therefore, the danger that any variety of damage can be generated in the region of the turbine rotor shell or the turbine rotor does not exist either. In addition, such an embodiment of the hydrodynamic coupling device according to the invention makes it possible to further reduce the number of parts and therefore to simplify its assembly.
As an example, it is possible to provide for the mating positive drive arrangement to comprise a plurality of drive apertures formed on the turbine rotor shell and for the positive drive arrangement to comprise a plurality of drive protrusions on a coupling element of the torsional vibration damper arrangement and integrally formed on it. In an embodiment variant which is particularly simple to manufacture, it is possible to provide for the drive apertures to be formed by engagement openings. These can, for example, be generated by punching or stamping.
According to a further aspect, the turbine rotor hub has an essentially sleeve-type first coupling region, radially located on the inside, for coupling to the drive element, and an essentially annular second coupling region for coupling to the turbine rotor shell.
According to U.S. Pat. No. 5,813,227, the two coupling regions of the turbine rotor hub are provided on an integrally configured component which can, for example, be manufactured by a casting process or can be brought to its shape by chip-removal machining. This, however, involves carrying out machining processes which are relatively complex and expensive and which lead to a high proportion of scrap, particularly in the case of chip-removal machining.
The invention therefore further proposes that the first coupling region and the second coupling region are components which are separately manufactured and permanently connected together.
Due to the design of the two coupling regions as separate components which have to be connected together, each of these components can be machined per se alone and can be manufactured from a material suitable for it. As an example, the annular second coupling region could be manufactured in a very simple and low-cost manner as a sheet-metal punched part. The two coupling regions can then be connected together by welding and, likewise, the second coupling region can be connected to the turbine rotor shell by welding.
According to a further aspect, the present invention relates to a hydrodynamic coupling device having a guide rotor arrangement with a guide rotor ring on which are carried a plurality of guide rotor blades and which is supported, on a support element, so that it can be rotated in one direction about the axis of rotation, by means of a bearing arrangement, for example a free-wheel arrangement.
In the hydrodynamic coupling device known from U.S. Pat. No. 5,813,227, a support or bearing ring is respectively provided on each axial side for the axial support of the guide rotor and of the guide rotor ring supporting the guide rotor blades, which support or bearing rings are, for example, held relative to the guide rotor ring by press-fit or/and by axial and radial support.
In order to be able to further reduce the number of parts in a hydrodynamic coupling device of this type, the invention therefore further proposes that a bearing section, which is axially supported on the turbine rotor or the casing arrangement, be integrally configured on the guide rotor ring. This bearing section can then, for example, be supported on the turbine rotor hub.
In order to ensure, in an arrangement of this type, that the working fluid necessary for the operation of the hydrodynamic coupling device can be guided into the internal space of the casing arrangement and can be withdrawn again from this internal space, it is further proposed that the bearing section should have at least one fluid duct to permit an exchange of fluid between a space region adjacent, radially on the inside, to the bearing section and a space region adjacent, radially on the outside, to the bearing section. The at least one fluid duct can be formed by shaping, stamping or the like.
In the coupling device according to the invention, furthermore, it is possible to provide for the free-wheel arrangement to comprise a free-wheel outer ring supporting the guide rotor ring and a plurality of free-wheel elements acting between the free-wheel outer ring and the support element.
In a preferred embodiment, furthermore, it is possible to provide for the free-wheel arrangement to comprise a free-wheel outer ring supporting the guide rotor ring and a plurality of free-wheel elements acting between the free-wheel outer ring and the support element. In this manner, it is possible, using simple structural measures, to maintain a fluid-tight drain between two space regions within the casing arrangement without, for example, having to provide a fluid-tight connection between the turbine rotor hub and the drive element.
In addition, it is possible to provide for the coupling element to be axially supported or to be able to be axially supported on the turbine rotor hub by means of a support element supported on the turbine rotor hub.
For further simplification of the assembly and/or to reduce the number of parts, it is furthermore possible to provide for the casing arrangement to have a pump rotor shell and a pump rotor hub integrally configured with the pump rotor shell.
According to a further aspect, the present invention relates to a hydrodynamic coupling device, in particular a hydrodynamic torque converter, including a casing arrangement and a turbine rotor which can be rotated about an axis of rotation in the casing arrangement. The turbine rotor has a turbine rotor shell which supports a plurality of turbine rotor blades, and a turbine rotor hub which is coupled or can be coupled to a drive element for joint rotation.
In such coupling devices, the danger exists that the casing will bulge out due to the fluid pressure existing within the casing arrangement so that in the presence of a lock-up clutch, for example, a friction surface provided on the casing is no longer in the desired position and local excessive wear of the same can therefore be generated.
In order to act against this, the invention further proposes that the casing arrangement should be provided with shape-stabilizing profiles in some regions.
The introduction of such profiles achieves a stiffening of the casing arrangement which acts against bulging of this type induced by fluid pressure. Particularly in the case where the casing arrangement is manufactured from sheet-metal parts, local hardening of the material can be obtained per se due to the reshaping of the same to form the form stabilization profiles by the generation of displacements within the lattice structure.
Particularly in the region of a pump rotor integrated into the casing arrangement or a shell of the same, it is possible to provide for at least a part of the shape-stabilizing profiles to be essentially arranged in the region radially between a torque transmission fluid circuit and the axis of rotation. As an alternative or additionally, particularly in the region of a casing cover, and if a lock-up clutch arrangement is provided for the optional transmission of torque between the turbine rotor and the casing arrangement and if a frictional surface region is formed on a casing element of the casing arrangement for interaction with a mating frictional surface region of the lock-up clutch arrangement, it is possible to provide for at least a part of the shape-stabilizing profiles to be arranged on the casing element in a region radially between the frictional surface region and the axis of rotation.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, and specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.
Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.